Apparatus for forming valve or tappet heads



Dec. 20, 1932.

Filed Nov. 7, 1929 INVENTOR ATTORNEYS Patented Dec. 20, 1932 NITED ES BRACKETT, F "DETROIT; MICHIGAN arrm'rusron' FORMING VALVE on TAPPETHEADS "Application filed November 7, 1929. Serial K064115317.

This .invention 'relates to an improved method of, and preferred apparatus for, "structurally correlating a relatively soft z'valve screw head or tappet member and a rela- 'tivelyharder inserted slug or impact receiv- 'ing piece, andhas'for its object not only the effecting of manufacturing economies per unitthus assembled,but.as well an increased efliciency'and permanency of the union between'the'parts thus effected. The relative degrees of hardness of the two parts thus joined may be-made a matter of selectlon '1 which is;determined' by the individual condi- "tions of anypartic'ular job in hand, and the operativemembers used in the manner herein pered as 'at'D. In this thus recessed die body there isadapted to belplaced a valve or tappet body G, whose screwthreaded stem F may depend rather loosely into the lower and smaller bottom portion of the bore B. The

diameter of the enlargement C is slightly less, except at its top edges D, than the external or peripheral size ofthe tappet head G, whose lower edge, when the member is first placed therein, rest non-descendingly about midway between the top and bottom of the enlarged bore portion C as a whole.

Gris bored, as at H, for the insertion of a slug J preferably of truncated conical shape, and

preferably the top of the tappet or valve body a G has been in the first instance so contoured that the making of the bore H leaves a slight The top surface of the valve or tappet head upwardly'T-projecting; rim as immediately surrounding the bore.

- Positioned in axial alignment above the holding d-ie A and' its insertedtappet-body .is a vertically descending dieibody L, in whose bored under'face is-inserted,byvscrew'threading'or otherwise, a terminally tapered im-, pact memberN, whose lower end,-which is adapted" to engage the top surface ofthe tappetbody, is'of the-same general curvature as the intended curvature of the tappet body when the process about to be described-is completed. The central-portion of'th-is tapered part N is centrally bored, as at P, for

the engagement therethrough of thestem'fQ of the yielding impact-member R which may be described as of cross-sectionallyT-shape.

This stem Q, is designed to descend, as the die-body'L as a whole descends, upon-and in axial alignment with the inserted slug J in" the top-of the tappet body, and, asbrought out in-Figure 1, in the initialstagesof the operation itextends below the slightly curved under face V of'the tappet-engaging part N, so-that the lower end of the stemuQe encounters the slug J slightly-before the under face of the valve-head-engaging body N encounters the top surface'ofthe val-vehead;

it thusserves to hold against displacement the slugJ which has previously been posi- 'tionedwithin the bore H in the top of-the va-lve'or tappet body. since however, im-

"mediately above thehead R of this descending'"T-shape piece there-is-positioned a cush- *ionTof rubberor other relatively yielding 'material, or even a spring -in;substitution therefor, as the die member L' continues this 'descent, the lower end-of thestem' Q'being already halted from further descent by its contactagainst the top of thejslug J,rthe rest of'the descending die member continues its downward movement, which from that timeon is'also downward relatively to the I slug-engaging stem Q, due to the yielding of the rubber filler'T or its equivalent spring? The lower" end "V of the tappet-engaging member N thus descends crushingly upon the metal of the tappet-head immediately surroun'dingthe bore H, and because of the slight .-;space left unoccupied" therein by the slightly? in the holding die A, so that when the driving stroke of the descending die member is finished, the tappet head'is very compact meta-llurgically with the sides of the bore H in its central part in firm holding engagement about the preferably sloping sides; of the insert or slug J. Whatever surplus metal of what was initially the rim K remains projecting to an undesired degree above the plane of the top surface of the head Gr may thereafter be ground off to the degree desired for neat finish.

his downward impact, to which the valve or tappet body as a whole has thus been subjected,having driven the valve or tappet body as a whole down to the bottom of the space C and its screw-threaded stem portion F having descended accordingly lengthwise of the bore B, the entire finished tappet may be ejected in any desired manner, as by up ward drive of the knockout punch member Y.

, As soon as the die member L is raised from the contact of its operative parts with the top of the tappet head, the resiliency of the rubber filler T or of the corresponding spring if thatbe used forces the T-shaped stein piece R and its stem Q, downwardly once more relatively to the bore P, so that its projecting lower end is again in position to operatively engagethe initially separate slug J which is positioned in the next tappet head blank G that is to be operatedupon. p

lVhat I claim is: V V

1. Means for effecting the structural integration of a body of relatively soft metal having a depression in its top surface and an inserted slug of harder metal in the depression comprising a holding die adapted to i hold insertedthe softer metallic body against centrifugal expansion in the presence of pressure applied to the top surface thereof, and a compositedie member having a downwardly projecting portion adapted to first yieldingly enga e the top of said slug when the die member as a whole descends, after which the impact and continued pressure ofthe other portion'of the composite diemember upon the top surface of the positioned soft metal body acts to force its component metal surroundim its bore centri etall 1 into firm holding engagement against thesides of the hard metal slug.

2.Means for effecting the structural .correlation of. a metall c body having an open cavity in its top surface, and an nserted slug,

said means comprising a holding die within which such parts so assembled are adapted to be rested, and a descending composite die member adapted to forcibly descend thereupon, such action causing flowage of part of the metallic body to cause seizure of the slug thereby, said descending die having a yieldably downwardly projecting extension adapted to engage the slug before the remainder of the die contacts the metallic body to retain the slug in position during the remainder of the operation.

3. Means for securing a slug in a tappet head having an aperture therein for loosely receiving the slug, comprising a holding die, a composite descending die member adapted to cooperate with the holding die in effecting the centripetaliflowage of the metal "of the tappet head surrounding saiddepression about said slug, and a stem carried by saids descending die member and projecting down- H therefrom to engage the slug before the remainder of the die contacts the tappet head, to prevent the slug from. undesirably changing its position under the impact of the; descending die.

i. he combination, with a holding die wherein there is adapted to be positioned a centrally bored tappet bolt whose headis of slightly greater diameter than that of the: bore in said die, of a descending die member positioned in axial alignment therewith and adapted to force the tappet bolt thereinto with a centripetal flowing influence upon the constituent metal of its head, to cause seizure;

of a slug inserted in itsbore, said descending die member being formed of a plurality of relatively movable parts one of which is adapted to impactingly engage the head of said tappet bolt while another engages the top of a slug positioned in the bored top of the tappet bolt before the other part strikes, and means yieldably maintaining said part inengagement with the slug during theremainder of the operation to prevent displacement of the slug. I I

In testimony whereof I sign this specification. CLARE L. BRACKEIT. 

